And as usual with these nice simple narratives, there's no evidence this actually happened (and compelling evidence that it didn't):
https://www.reddit.com/r/AskHistorians/comments/pmjrdg/is_th...
https://www.reddit.com/r/AskHistorians/comments/pmjrdg/is_th...
[1] https://en.wikipedia.org/wiki/Great_Hanoi_Rat_Massacre#Hirin...
[1] https://www.theguardian.com/us-news/2022/oct/11/new-york-gun... [2] https://www.vice.com/en/article/akee4e/someone-made-dollar30...
It's not due to a perverse incentive regardless, though, which is what the original anecdote is supposed to exemplify.